1. Field of the Invention
The disclosure generally relates to a mobile device, and more particularly, relates to a mobile device comprising an antenna structure.
2. Description of the Related Art
With the progress of mobile communication technology, mobile devices, for example, portable computers, mobile phones, tablet computer, multimedia players, and other hybrid functional portable electronic devices, have become more common To satisfy the demand of users, mobile devices usually can perform wireless communication functions. Some functions cover a large wireless communication area, for example, mobile phones using 2 G, 3 G, and LTE (Long Term Evolution) systems and using frequency bands of 700 MHz, 850 MHz, 900 MHz, 1800 MHz, 1900 MHz, 2100 MHz, 2300 MHz, and 2500 MHz. Some functions cover a small wireless communication area, for example, mobile phones using Wi-Fi, Bluetooth, and WiMAX (Worldwide Interoperability for Microwave Access) systems and using frequency bands of 2.4 GHz, 3.5 GHz, 5.2 GHz, and 5.8 GHz.
Traditionally, a metal element with a fixed size is used as a main body of an antenna. The metal element is one-second wavelength or one-fourth wavelength in length, wherein the wavelength corresponds to the desired frequency band. Generally, an antenna corresponding to a low band (e.g., a GPS (Global Positioning System) band) usually has a large size and cannot be designed in a small mobile device.